Performance evaluation of an absorption refrigeration system using R1234yf - organic absorbents working fluids

Abstract

This study proposes the use of hydrofluoroolefins and organic absorbents mixtures as a working fluid pair in a single-effect absorption refrigeration system. In the refrigeration cycle, the 2,3,3,3-tetrafluoropropylene (R1234yf) is used as a refrigerant, and the triethylene glycol dimethyl ether (DMETrEG) and N-methyl-2-pyrrolidone (NMP) are used as absorbents. The working fluid’s thermophysical properties and the verified thermodynamic models are presented in this paper. This study illustrates the effect of the generator temperature (330.15–365.15 K), absorber temperature (293.15–313.15 K) and evaporator temperature (268.15–283.15 K) on the coefficient of performance (COP), the circulation ratio and the solution concentrations. Among the most prominent results of this research are that the COP is between 0.053-0.409 for the mixture containing the DMETrEG, while it is between 0.025-0.333 for the mixture containing NMP. The R1234yf-DMETrEG mixture is recommended based on the overall performance, circulation ratio and stability, followed by R1234yf-NMP mixture. The effectiveness of R1234yf-organic absorbents is lower than those of R134a and R152a with the same absorbents. Therefore, the incorporation of a compressor to assist the absorption cycle can improve the COP of the cycle and extend the operation range of the proposed R1234yf-DMETrEG mixture.